Emergency services received a report at around 4 pm that people were trapped in the Chem drainage system on Lien Mac Street in Dong Ngac Ward.
A rescue vehicle and a fire engine were dispatched to the scene, where police found two people trapped inside the pipe.
Fire and rescue officers, working with local police and residents, used specialised equipment to reach the pair.
Both were brought to safety at around 5 pm and were in stable condition, police said.
Authorities are investigating how they became trapped.
In a separate incident in the same area on September 17, a first-year university student was believed to have been swept into a drain while riding his motorbike through a deeply flooded street.
The area was heavily flooded and had few passers-by at the time. His body was recovered the following day.
